This invention relates to a vibration damper, preferably to be used in motor vehicle wheel suspensions, the damping effect of which can be changed by the intensity of an electrical field applied to a volume of a electrorheological liquid.
Modern motor vehicles, in particular top-quality motor vehicles, are equipped with adjustable vibration dampers in order to achieve, on the one hand, a soft chassis setting for comfort in travel and, on the other hand, a taut sports setting for the range of higher speeds of travel. It is possible, for example, to equip the damper with damping valves of which the damping power is adjustable via electromagnets. These damping valves are very complicated in construction and correspondingly expensive and sensitive. Alternatively, vibration dampers are known which contain an electrorheological medium which changes its viscosity under the influence of a high voltage within a capacitor arrangement. The variable viscosity of the medium is the basis for the adjustable damping. The electrorheological medium is simultaneously used as a control medium and as a damping medium.